FDA sidesteps safety concerns over TSA body scanners

Some professors recently expressed concern about the safety of the TSA's new X …

The United States Transportation Security Administration has recently come under scrutiny for, among other things, its use of X-ray full-body scanners in airports to see through clothes and to detect non-metallic explosives. But are they safe? A group of UC-San Francisco professors recently raised a number of safety concerns regarding these scanners. While the Obama administration attempted to address these worries, its assertion that the scanners are safe appears to fall short.

The TSA has slowly been implementing the use of X-ray scanners in airports (so far, 38 airports have 206 of the machines) in order to see through passengers' clothes and check them for explosive devices. Officials have asserted that the machines are okay to use on the basis of the everyday use of X-rays in medical offices. However, a group of four UCSF professors pinpointed several important differences between the medical X-ray machines and those used in airports. They described the issues in a letter to Dr. John P. Holdren, the assistant to the president for science and technology.

A normal X-ray image is a familiar sight—depending on the exposure, an X-rayed person typically appears only as a skeleton. This is because the X-rays used in those machines penetrate the skin and can only scatter off of the larger atoms in bones.

Unlike a medical X-ray, the TSA X-ray machines are a sci-fi fan's dream: they are lower-energy beams that can only penetrate clothing and the topmost layers of skin. This provides TSA agents with a view that would expose any explosives concealed by clothing. But according to the UCSF professors, the low-energy rays do a "Compton scatter" off tissue layers just under the skin, rather than the bone, possibly exposing some vital areas and leaving the tissues at risk of mutation.

When an X-ray Compton scatters, it doesn't shift an electron to a higher energy level; instead, it hits the electron hard enough to dislodge it from its atom. The authors note that this process is "likely breaking bonds," which could cause mutations in cells and raise the risk of cancer.

Because the X-rays only make it just under the skin's surface, the total volume of tissue responsible for absorbing the radiation is fairly small. The professors point out that many body parts that are particularly susceptible to cancer are just under the surface, such as breast tissue and testicles. They are also concerned with those over 65, as well as children, being exposed to the X-rays.

The professors pointed to a number of other issues, including the possibility that TSA agents may scan certain areas more slowly (for example, the groin, to prevent another "underwear bomber" incident like the one in December 2009), exposing that area to even more radiation. But the letter never explicitly accuses the machines of being dangerous; rather, the professors encourage Dr. Holdren to pursue testing to make sure that the casual use of these X-rays is safe.

Dr. Holdren passed the letter on to the Food and Drug Administration for review. But, in the FDA's response, the agency gave the issues little more than a data-driven brush off. They cite five studies in response to the professors' request for independent verification of the safety of these X-rays; however, three are more than a decade old, and none of them deal specifically with the low-energy X-rays the professors are concerned about. The letter also doesn't mention the FDA's own classification of X-rays as carcinogens in 2005.

The letter concludes that "the potential health risks from a full-body screening with a general-use X-ray security system are minuscule." But the increased surface area and volume of absorption area, plus the frequency with which many people travel, suggests that this use at least bears further scrutiny. US pilots' associations have also encouraged their members to opt for the pat-down in the meantime.

Of course, these pat-downs have recently become rather invasive, so now travelers must choose between a little irradiation and being felt up by a non-doctor.

However, the TSA does have a potential solution in hand. Of the 68 airports scanning for explosives, 30 are using millimeter-wave scanners that don't use X-rays at all; they hit the surface of the body with safer radio waves. If the TSA committed to using only this type of equipment, it could avoid the safety concerns regarding the X-ray full body scanners completely.

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Also, is there a way to visually identify one vs. the other? Example (made up): an xray scanner has to have opaque sides, where a millimeter one is usually lightly tinted glass. This information would make it easier to opt-out of the xray scans, but pass through the mWave ones (if you so choose).

Edit 2: Answering my own question, here's a quote from the forum posted below by BlackClaw:

BKSX usually looks like two large solid blocks facing each other with a gap in the middle. MMW usually looks more like a cabin or a tube to stand in.

Hopefully you all find that helpful and I haven't abused my #1 position too much ;- )

now travelers must choose between a little irradiation and being felt up by a non-doctor.

Just calling them "non-doctors" is a lot more generous than I'm inclined to be.

Think I'm going to write a letter tonight, send it the the CEO of United and maybe my congressional representative, letting them know that in light of the new security procedures, I'm making an 11 hour drive for the holidays rather than flying.

The same FDA that banned the amino acid Tryptophan for years, b/c a bad batch showed up once from a processing facility that got sloppy. However, they GRAS things like aspartame & msg, which are excitotoxins that slowly destroy the brain and alter food cravings, and letting states auto-medicate the populace with fluoridated water, even though fluoride has been shown to damage the endocrine system and promote brittle bones. The FDA tends to have awkward priorities.

More on topic, are little kids subject to full body scans and pat downs? If not, then terrorists will just raise kids to carry the explosives. If they are, then it's a more long-term health risk for the child (being exposed to the x-rays), and the pat-down if refused would be very awkward.

Meanwhile, that one guy who filmed this stuff showed that if you refuse both scan & pat-down, then your only alternative is a threat of a $10k civil suit. I think the travel holidays are going to be a feeding frenzy for the media this year when tons of folks blow up over this stuff.

Also, is there a way to visually identify one vs. the other? Example (made up): an xray scanner has to have opaque sides, where a millimeter one is usually lightly tinted glass. This information would make it easier to opt-out of the xray scans, but pass through the mWave ones (if you so choose).

When I was in DFW recently, there are signs all over the place in the line up to the machine warning about them. If you're paying any attention at all, you can't not notice. The signs specifically state something along the lines of "This airport uses Millimeter Wave detection systems for imaging passengers. If you are not comfortable passing through this device, you may request an individual pat-down search instead."

I don't know about airports with X-Ray scanners, but I would assume they have the same sign, except changing the name.

It's been known for some time now that the majority of future installations (1000 machines by the end of 2011) are going to be X-Ray Backscatter, *not* Milimeter Wave. They were testing both and then settled on the X-Ray machines.

The company that makes the backscatter machines, Rapiscan, is a consulting customer of former DHS secretary Michael Chertoff, who went on the talk show circuit in January of this year talking about how much we needed these machines to be safer...

I'll let folks draw their own conclusions about why the TSA decided to buy the machines that output ionizing radiation vs non-ionizing radiation....

I'm okay with being scanned. I'm okay with the pat-down. I am not okay with being subjected to radiation shot by a machine that has not had the proper testing to validate its safety.

++

I'm also not ok with having a hernia exam performed by some random person that is not a licensed physician.

It's just so sad that we have to give up our personal freedoms because people are such worry-warts. One person puts a bomb in their shoes, which fails. You now have to take off your shoes. One person puts a bomb in a couple of toner cartridges, which fails. Now you can't ship toner cartridges larger than 16". I'm surprised they didn't instate a "no undies" policy after the failed underwear bomber attempt. I mean seriously, if one particular way failed, why would they try it again? Honestly I think the purpose was to fail just to make our lives more miserable and lose more freedoms.

I hadn't heard of the other type of scanner. More information is very welcome....and what airports have them?

Millimeter-wave radar is described quite well in the futurist documentary Snow Crash by Neal Stephenson. It is quite effective at finding metal underneath clothing, but has difficulty detecting shards of glass.

I'm okay with being scanned. I'm okay with the pat-down. I am not okay with being subjected to radiation shot by a machine that has not had the proper testing to validate its safety.

++

I'm also not ok with having a hernia exam performed by some random person that is not a licensed physician.

It's just so sad that we have to give up our personal freedoms because people are such worry-warts. One person puts a bomb in their shoes, which fails. You now have to take off your shoes. One person puts a bomb in a couple of toner cartridges, which fails. Now you can't ship toner cartridges larger than 16". I'm surprised they didn't instate a "no undies" policy after the failed underwear bomber attempt. I mean seriously, if one particular way failed, why would they try it again? Honestly I think the purpose was to fail just to make our lives more miserable and lose more freedoms.

I flew out of JAX (FL) after they had first installed them for a trial and before they were required to post pictures of what the scan exposed. Two later trips through that airport I was not asked to enter the scanner -- they seemed to be using it randomly, or not at all.

The same FDA that banned the amino acid Tryptophan for years, b/c a bad batch showed up once from a processing facility that got sloppy. However, they GRAS things like aspartame & msg, which are excitotoxins that slowly destroy the brain and alter food cravings, and letting states auto-medicate the populace with fluoridated water, even though fluoride has been shown to damage the endocrine system and promote brittle bones. The FDA tends to have awkward priorities.

That tryptophan scare killed 38 people it was far from obvious what the source was. Several countries followed suit, so it wasn't just the "crazy" FDA deciding this. The move was the right thing to do and I say this as someone who take Tryptophan nightly for insomnia.

Err, artificial sweetners are safe contrary to the naturalist bullshit claiming everything from cancer to brain disease in humans from drinking Diet Coke. Fluoride is especially safe and saves a lot of poor people from suffering from serious dental problems. Over-fluoridation has risks, but generally most people will never get too much fluoride from a properly run fluoridation system.

I get it. You're Mr Conspiracy Theory Naturalist with an axe to grind with any regulatory agency that doesn't buy your brand of homeopathic bullshit. You're far from convincing.

I hadn't heard of the other type of scanner. More information is very welcome....and what airports have them?

Millimeter-wave radar is described quite well in the futurist documentary Snow Crash by Neal Stephenson. It is quite effective at finding metal underneath clothing, but has difficulty detecting shards of glass.

That's funny, I've taken multiple glass objects on planes packed in my luggage. Any one of those could have quickly turned into a shard. Are they going to prohibit glass now? What about aluminum cans...those can make some deeeep cuts.

"Ok - now that you're completely naked, and you've shipped your belongings via overnight express, you can board the plane and take your seat on the floor indian style in our newly refinished 'sparse-modern' cabin. We will not serve you beverages, and there is no bathroom -- so take care of that first. There also aren't flight attendants because we couldn't hire people that wanted to work naked. Have a nice flight"

What bothers me is that the backscatter machines cost $100K to $200K per machine, and who know how much to operate and maintain. I rather have an airport use current metal detection and hire out trained sniffing dogs and have them aggressively inspect and interview passengers than waste money on machines that have unknown health consequences.

Besides which, the humilation and invasiveness of these machines is absurd when you consider that all this money is going to protect just one piece of infrastructure, when pretty much every other piece is wide open to abuse (for example, our port security is a joke).

I can tell you this, I will avoid flying as much as possible, and use the pat-down option when I do.

You just made my point. If C4 is stuffed up your colon it won't show up on this thing. Again it scans the outside of the body. Not inside. Next up full body, down to the bone scans. Cancer...bah....its so worth it to secure a plane.

What a mess. I think I'll try to take a train next time or take piloting lessons so I can fly myself where I need to go. Good thing I don't travel much. I understand the need for safety, but there really should be more evaluation and certification of machines.

Think I'm going to write a letter tonight, send it the the CEO of United and maybe my congressional representative, letting them know that in light of the new security procedures, I'm making an 11 hour drive for the holidays rather than flying.

Me too. Although it's only 9h, And it's not only because of the security procedures, but because, in one of the most densely populated states in the US (California), the placement of the airports is just so unpractical, it's actually faster to drive. Even though driving 9h with 2 bored, bitching and fighting teenagers in the back is a real nightmare (not that I would like to force it on fellow plane travelers either).

Yet, the percentage of travelers dying while in transportation is lower for planes than it is for cars. Hence, cars are a more dangerous mode of transportation, risks of terrorism included, than planes. Are you required to submit to crazy security measures before boarding your car? No. Basically everyone, even alcoholic, half blind and borderline retarded, can get a license, and drive a 2 ton hunk of metal at 60mph on highways. Putting everybody else at risk. But that is OK, right?

Meanwhile, safe, fast, comfortable, planet-friendly and family-friendly alternatives like the California High-Speed Rail are getting shot down by basically everybody. Public transportation?? So unamerican!

More on topic, are little kids subject to full body scans and pat downs? If not, then terrorists will just raise kids to carry the explosives. If they are, then it's a more long-term health risk for the child (being exposed to the x-rays), and the pat-down if refused would be very awkward.

Little kids are subject to full body scans and pat downs. It's partly random who gets the extra security, and whether a scan is part of it just depends on whether the airport has the equipment. See http://www.myvidster.com/video/600891/V ... Checkpoint for some interesting details. I have a four-year-old, and I definitely will opt out of the optional head x-ray, even if I didn't find the whole random strip search idea revolting.

As for raising kids to carry the explosives, I think that's an interesting movie plot, but not at all likely in practice. It's a pretty big investment to raise a child for even a few years, and mothers and fathers tend to be rather fond of them. And there's really no point anymore. Even if you get a bomb aboard a plane, the passengers are not going to let you get control. So you could blow up a plane and all of the passengers, but not use the plane as a weapon as on 9/11. Or you could pack your rolling suitcase with whatever weapon you can get your hands on and roll it right up to the hundreds of people waiting to go through security, or if you're a little bolder, past the guy who checks the boarding passes and right up to the very expensive scanners. It's frustrating that airport security seems to be about violating our rights for show, while doing nothing to make us actually safer.